This system is a 64 bit Windows 10 system running on a Gigabyte GA-990FXA-UD3 UEFI motherboard with an AMD 3.50 GHz FX-6300 six core CPU running with 8GB of DDR3. The C: Drive is a Kingston SUV400S37240G 240GB SSD with a 4TB D: drive. The Windows 10 Pro is version 1903, build 18362.267 installed on 9Aug2019 & fully updated.I successfully installed Xp SP3 with the same settings as I tried to use to install Ubuntu.

I have tried several times to install with the install failing at various points.

1. It has failed to find the Start Up Disk.2. It has found the Start Up Disk but has failed before I got all the way through the details of my location etc3. It often stops with a pointer looking like a capital I & will not accept keyboard entry or mouse entry.4. It has got all the way through the details of my location etc & started to install but the rotating symbol showing that the program is installing just stops dead. Leaving it an hour did not help.

I deleted the Ubuntu completely & tried reinstalling several times.This last time it has gone through the furtherest ending at this screen:

Installation type This computer currently has Ubuntu 18.04.3 LTS on it. What would you like to do? O Erase Ubuntu 18.04.3 LTS and reinstall Warning: This will delete all your Ubuntu 18.04.3 LTS programs, documents, photos, music, and any other files.

The erase option is selected but it will not accept any further input.

Disk is created exactly the same as it has been when I successfully did a Windows Xp SP3 Virtual OS system for testing.I then power Ubuntu On.Select Start Up Diskubuntu-18.04.3-desktop-amd64.iso (1.94GB) This is 64bit as well Location: C:\Users\brian\Downloads

You sound like a fairly new user to VirtualBox. Since you are expected to know some basic terms before we engage in a meaningful discussion, I would suggest to start by reading three small chapters from the User Manual:

Do NOT send me Personal Messages (PMs) for troubleshooting, they are simply deleted.Do NOT reply with the "QUOTE" button, please use the "POST REPLY", at the bottom of the form.If you obfuscate any information requested, I will obfuscate my response. These are virtual UUIDs, not real ones.

What isn't installing? Did you follow the instructions? The idea is relatively simple, I'll summarize it:

Create a new VM. Select carefully the Type and Version. For example Linux, Ubuntu 32 or 64 bit.

Stick with the proposed defaults until you get it going.

Start the VM, you'll be prompted where to boot it from. Select the ISO that you downloaded. You ... did download an Ubuntu ISO, right?

Select not the Live option, but the option to Install it to your hard disk. That's the virtual hard disk not the physical one on your host.

Follow the prompts, reboot the VM, done.

Do NOT send me Personal Messages (PMs) for troubleshooting, they are simply deleted.Do NOT reply with the "QUOTE" button, please use the "POST REPLY", at the bottom of the form.If you obfuscate any information requested, I will obfuscate my response. These are virtual UUIDs, not real ones.